Recently we developed a non-lithographic approach for fabrication of microfluidic devices. The novel non-lithographic methods allow us to achieve not only expedience in the device prototyping, but also facile coupling of the fabricated microfluidic devices to photonic and electronic sources and detectors. In a single and facile fabrication step, we were able to place channels with complex tree-dimensional connectivity within the bulk volume of a single polymer component of a device. With the traditional photolithographic approaches, such connectivity can be achieved by fabrication of multiple components that are assembled under stringent alignment requirements. Using the non-lithographic fabrication methods, developed in our laboratory, we prepared continuous-flow microfluidic devices for detection of vegetative bacteria and bacterial spores. The need for expedient quantitative detection of bacterial endospores and vegetative bacteria is paramount for areas such as healthcare and defense against bioterrorism. We have developed spectroscopic approaches for detection of bacterial spores based on emission enhancement of metal ions or ionic dyes in the presence of the molecular moieties unique to the spores. We observed that application of such emission techniques to detection of vegetative bacteria yields kinetic components of the enhancement processes that can be characteristic to the particular organisms. Relating the molecular structural features of the used chromofores to the observed kinetic reactivity allows us to gain mechanistic understanding on the interaction of various bacteria with the external environment. The dynamic nature of microfluidics, allowed us to develop devices for time-resolved measurements based on inexpensive steady-state sources and detectors. We utilize the developed devices for sensing of various bacterial species based on the kinetics of interaction with the different fluorophores.

Extended Abstract Status: Not Uploaded